Volume Could Not Be Unmounted Disk Utility: A Solution Using TestDisk and fsck_hfs

As a Mac user, you're likely familiar with the frustration of encountering an unmountable disk utility issue. This problem can occur due to various reasons such as corrupted file systems or disk errors. In this article, we'll explore how to resolve the 'volume could not be verified completely' error using TestDisk and fsck_hfs.

My Journey to Resolve the Issue

I recently encountered this issue with my 1TB Mac OS Extended External Hard Drive on my MacBook Air 13' running MacOS Catalina 10.15.7. The drive was almost full, which made it even more challenging to troubleshoot the problem. After running a quick search using TestDisk 7.1, I found that the total sectors for the embedded volume were 0.

The initial scan revealed that the volume could not be verified completely. However, this didn't discourage me from finding a solution. I decided to use fsck_hfs (version hfs-522.100.5) to repair the disk. Here's the command I used: `sudo fsck_hfs -r -d /dev/disk2s2`.

The output showed that the journal_replay() function returned 0, indicating a successful repair. Unfortunately, when I tried to verify or repair the volume using the same command, it failed again with the message 'The volume could not be verified completely.'

Running First Aid on Disk2s2

I decided to run First Aid on disk2s2 to see if it would resolve the issue. However, this resulted in an 'Invalid catalogue PEOF' error. At this point, I was starting to lose hope.

Mounting the Drive Partially

When I ran `fsck_hfs -r -d /dev/disk2s2`, the drive partially mounted onto my MacBook Air (disk2), but the actual drive itself (disk2s2) refused to mount. This led me to believe that there might be a deeper issue with the file system.

Finding a Solution Using TestDisk and fsck_hfs

After some research, I came across an article suggesting the use of TestDisk and fsck_hfs to resolve similar issues. I decided to give it a try. Here's what worked for me:

1. Run `TestDisk 7.1` on the affected drive.

2. Use the 'Quick Search' option to scan the disk.

3. Once the scan is complete, use the 'Open Disk' option to access the disk's contents.

4. Navigate to the 'Embedded Volume' section and check if it has any sectors allocated (in my case, it didn't).

5. Run `fsck_hfs -r -d /dev/disk2s2` as I mentioned earlier.

By combining these steps, I was able to successfully repair my external hard drive and make it mountable again.

Resolving the 'volume could not be verified completely' error requires patience and persistence. In this article, we've seen how TestDisk and fsck_hfs can be used to troubleshoot and repair disk utility issues on Mac OS Extended External Hard Drives. If you're facing a similar issue, I hope this solution helps you get your drive up and running again.

Volume could not be unmounted disk utility